Keybase gets confused if I change my mind about my key

STR:
- Accept an invite
- Go to upload your key
- Copy and paste ASCII public key block
- Move on in process
- Get to "key verification" step
- Realise you've pasted the wrong key (an old, weak one)
- Cancel process
- Start process again
- Copy and paste correct key block
- Move on in process
- Get to key verification step

Problem: the key verification instructions I get (the long command line to sign the JSON blob) refers to the first key, not the second key.

Gerv

Reproduce the invite flow using the STR: upload one ASCII public key, cancel at key verification, restart, and upload a different key. Inspect how the uploaded key is retained between attempts and how the key-verification command is generated; done means the second key is referenced after restarting the process.

Written by the indexing model from the issue text.